I personally don't like my mount to wobble, so I like my wire to be recessed inside a groove at the back of the wood. I drill my hole just big enough for my wire, and then take an electric wood chisel and make a channel that the wire will sit into. I make the channel like three inches long coming down from the first hole, and then drill a second hole (not completely through the wood) at the bottom of the channel. Now I take my wire, and push it through the hole , bend it down, and cut it so it is a bit longer than the channel I have made, I bend it again, and shove the last bend back into the second hole I drilled. Hammer it into place, and the wire is flush, and not going anywhere. You can tack the top of the wire if desired with a small wood screw where the wire come through the first hole. I personally have done it both ways, but don't find it necessary. the other thing I do is take a wood drill bit and recess three holes in the back of the wood (in the shape of a cheap hanger) where I can set my hanger in the holes I have countered, screw these into place, and the hanger won't allow the mount to wobble either.
-Pete